Reproducer for talking-machines



W. T. LAKIN.

nmonucan roa TALKING MACHINES.

APPLICATION FILED APR. 3| 1919. 1,393,298

J Patented, Oct H, 1921,.

. IIIII/ENTOR b iz-ziamzm m AUOIWEYS WILLIAM. T. LAKIN, OF LONG, MARYLAND.

REPRODUCER FOR TALKING-MAGHIN ES.

.ducer having a balanced needle bar capable V of lateral adjustment in the direction of vi- .Fig.

bration of the diaphragm, to vary the pressure on the diaphragm and consequently alter the pitch.

A further object of the invention is to provide a reproducer having a balanced needle bar fulcrumed in the plane of the diaphragm. j

Other objects and advantages will appear in the following specification, reference being had. to the accompanying drawings, in which Figure 1 is an elevation illustrating the first form of a reproducer constructed in accordance with my invention,

Fig. 2 is a. detail sectional view illustrating the adjustable needle bar mounting,

Fig. 3 isa section on the line 3-3 of Figs. 4:, 5 and 6 are detail views of modifications of the bearing pin structure, Figs. 7 and 8 are detail views of one of the needle bar adjusting screws alsoshowing the various bearing pin recesses in the crossed kerfs,

Fig. 9i's an elevation of the second form of the reproducer constructed in accordance with my invention, 1

Fig. 10 is a detail sectional viewshowing' the needle bar mounting,

Fig. 11 is a section on the line 11-11 of Fig.10,

1 Fig. 12 is an elevation of the third form of a reproducer constructed in accordance with my invention,

Fig. 13 is a detail cross section on the line 1313 of Fig. "12, andfFig. 14 is a detail view of a further modification of the bearin pin. 5

n so far as the first form of the reproducer illustrated in Figs. 1 to 6 inclusive is Patented Oct. if, 1921.

Application fi1edApril18, 1919. Serial No. 291,088.

concerned, this application shows structure disclosed in my Patent 1,301,458 of April 22, 1919, this structure being identified by the brackets 53, a needle bar 54: and flexible bearing pins 51, adjustably mounted in said brackets to support said needle bar and enable a freer rocking motion thereof. lln order that the construction of the three forms of the reproducer, all of which embody the same principles may be understood, attentlon is first directed to The first form of the invention in F 2'98. 1, 2 and 3.

Here the reproducer 1 is shown to consist of a circular frame 2 which is internally rabbeted at 3 in Fig. 3, to provide a flange 1 against which the outermost circular compressible insulating annulus or cushion 5 bears. The diaphragm 6 fits against the cushion 5 in the frame 2 and is securely held in place under pressure by means of a back 7 with an interposed compressible annulus or cushion 8 similar to the other cushion 5.

Screws 9, or equivalent fastening means, are employed to compress the cushions 5 and 8 against the periphery of the diaphragm. As can be plainly seen in Fig. 3, the back 7 includes a portion which fits inside of the bore or rabbeted portion 8 of the frame 2-, and a flange 10, which is slightly spaced from the edge of the frame at'll, leaving room for adjustment or further compression of the cushion, as indicated above.

The circular cushions 5, 8 are made of rubber or any other material suitable for the purpose of sustaining the increased pressureon the diaphragm 6, required to assist in maintaining the pitch proportionately as the diameter of the diaphragm is- .increased. In actual practice it is desired to use the largest diaphragm that it is possible to employ within the range of practicability. Any resultant lowering of the pitch by reason of the increase in the size of the diaphragm, can be compensated for by in creasing the pressure on the supporting compressible cushions 5, 8. Itis to be understood from the foregoing, that. the pressure on the diaphragm of a particular sound. box is constant and fixed, the provision for the increase of pressure relating to circumstances where the diameters of sound boxes and diaphragms vary.

The same act of increasing the pressure on the periphery of the diaphragm by virtue of tightening down on the screws 9, also increases the pressure on the stylus bar or lever 12 against the diaphragm. This iii-- creases the resistance and consequently elevates the tone, but not to the extent of hindering vibration. Naturally, a low pitched reproducer will reproduce the low notes more accurately, and on the other hand, 'a highv pitched reproducer will re produce the higher notes more accurately but with less amplitude. Conversely. the greater the diameter of the diaphragm within certain limits, the greater will be the amplitude, the lower the pitch, and less marked the scratch.

The explanation set forth in the foregoing paragraph shows the result of many tests with this reproducer, and is given for the purpose of making the manner of operation of other structure in the reproducer more clear and evident. To this end, the description of the reproducer structure is now resumed.

Brackets 53, formerly referred to, include bases 13 with slots l t through which screws 15 are screwed into the frame 2 and enable adjustment of the brackets so that the bearing structure of the needle bar may be more accurately alined. They also include heads 16 in which the flexible bearing pins 51 are mounted.

For this purpose, each head has a threaded opening into which the bearing pin is screwed. as shown in Fig. 2. The bearing pins are capable of adjustment, and include jam nuts 17 by means of which the adjustments are fixed. Each bearing pin includes a flattened portion which terminates in a conical point 18.

There is a pair of the conical pointed flexible bearing pins 51, one in each bracket 53 as shown, and these provide the support on one side for the stylus or needle bar,

which is in the shape oi? a cross head and occupies the space defined by the portions of the brackets 53. .x ecdle bar adjusting screws 20 are screwed into the extremities of the needle bar 19, and. have heads 21 with crossed kGIfS 22 with a series of recesses 23 running in both directions, to receive and sustain the conical points 18.

As will immediately appear. the needle bar 19 is subject to adjustment in the direction of vibration of the diaphragm for the purpose of causing the stylus bar 12 to alter the pitch of the sound, and this adjustment of the needle bar is obtained by making the proper ones of the bearing pin recesses 23 to occupy positions on the conical point 18, so that the needle bar is either flexed forwardly or backwardly, as the occasion may require. 7

One of the most important structural features of the reproducer is well illustrated in Fig. 3, wherein the needle 24, the .fieXib-l bearing pins 51, the needle bar adjusting screws 20, the diaphragm t3, and the i'ulcruin screws are shown to he in direct vertical alinement. The 'i'ulcrnni scrcws. oi which there are two. are coaxially alincd with the flexible bearing pins as shown in Fig. and have wedge-shaped or chisel points so to occupy similarly shaped koris or grooves 27 in the upper extremities oi the needle bar 19.

Instead oi? making the points 26 wedgeshaped or chisehpointed. as shown, th y may be made conical-pointed and serve the purpose equally as well. The fulcrum screws- 25 are introduced and adjusted in position. from the inside of: the frame 2' in the pre ferred construction, and obviously they may be fixed in place in any other equivalent manner.

The flexible bearing pins 51 are subject to some modification. as indicated in Fig. at, 5 and 6. In Fig. 4, the hearing pin has a threaded bore 49 into which the left-hand threaded extension 4-8 screws. The extension 18 is a part of thc righhhand threaded screw head 16, by means oi which this form of the bearin pin is introdiu-ed in position, when the two parts are screwed together, by the means shown. This 'i'orni of bearing pin is longer than the others. and is shown to illustrate how any desired position of the flattened sides can be ohtaincd without changin the l'lllCI'iIlll pins 26. The threads on the bearing pin being in opposite directions, admit of such adjustment.

The form of the bearing pin in Fig. :7 is substantially like that in Fig. 2', with the exception that the point 18 is not conical in the sense that the sides are flat, but is made conical with rounded or curved sidcs. In Fig. 6, the bearing pin 51 has a restricted, portion 52 terminating in an oval-shapcd and pointed tip Fig. 14 shows another form of hearing pin which is adapted more particularly. for the larger reproduccrs employing long stylus bars. The purpose of this pin is to keep the stylus bar '19 from unscating iron] the fulcrum points in the reproduction of certain loud sounds. In use. one end m. threaded as shown, is screwed through an opening into either arm ot the stylus bar, and then screws into the edge of the frame 2 of the reproduccr. The other end of the pin is also threaded at and a centrally constricted portion 55 makes the pin flexible.

The second form in Figs. 9, 70, who I].

Many of the features in the foregoing st ruc ture, namely, in Figs. l. and 3 will he, rccognized in this second term oi the invention. Principally among these is the provision of the fulcrum screws 25 with the chisel points 26, which occupy the. kerts or grooves 27" lilil 1 to the bottoinf of the reproducer frame 2,

has lugs 16 extending at opposite sides and inpositions diagonally opposite each other, toprovide supports for resilient yokes 30.

If desired, the lugs 16 maybe formed integrally with the reproducer frame, but in either event, they provide the means by which the yokes are attached to the reproducer frame through the medium of the securingmeans 31. ,1

Thejneedle bar 19 has extensions 32 corresponding in POSltiQlltQ the lugs 29 and yokes 30, for ,the purpose of supporting bearing screws V51"- whichare' suitably actuated toflex or adjust the needle bar 19in one or the other direction on the fulcrum screws 25f As' can be plainly seen in Fig. 11, the bearing. screws; 51 are screwed into the bent over ends of the spring yokes 30, andv obviously, as the screws 51 are tightened or loosened, the needle bar 19 will be adjusted either forwardly or backwardly with a corresponding influence on the stylus bar 12.v

Here too it is to be observed that the needle 24, the fulcrum screws 25 and the diaphragm 6, are in alinement. Of course, by virtue of this particular construction, the

means for adjusting the needle bar is not located in the same plane with the other de- 'vices mentioned. But it is to be observed that in this form, the adjusting means is distributed laterally of the plane of. alinement of the needle, fulcrum screws 25 and diaphragm, so that the same balancing ef-. fectis obtained in this second form as in the first.

The third form in Figs. 1.? and 13.

form of the invention, the principal dif ference being that in this latter form, the

parts are more condensed. Instead of ex-.

tending the resilient yoke as in Fig. 11, the yokes 30 in Fig. 13 are kept relatively close to the inside of the brackets. The yokes 30 are secured beneath or on the upper side of each arm of the needle bar 19 by the fastening means 31 which occupies the slotted end 33 of the yokes. The other end of each yoke has a minute recess 23 to receive the conical point 18 of the bearing pins 51.

It is also to be observed that the bearing pins 51 are offset in position instead of being in alinement with the diaphragm 6, to

this extent corresponding approximately to in axial oppositiontin accordance with the definition of the term as herein employed) Similarity of principle.

1 As has been stated before, the underlying principle is the same in all three forms of the invention. This similarity of principle resides in the lateral adjust-ability'of the needle bar 19 whereby the pitch of thesound is altered by virtue ofvarying the pressure on the diaphragm through the stylus bar 12.

In Fig.3, thisobject is attained by adjusting the needlebar 19 either forwardly or backwardly on the fulcrum'screws 25, and setting the point of the bearing pins: 51 in the proper ones of the recesses 23. The provision of the recesses enables the holding of the adjustment when the proper adjustment is once arrived at. Ordinarily, the bearingipin points will occupythe position in the center at the intersection of thekerf 22, but as stated before, in order to flex the stylus bar 12 forwardly or backwardly, the bearing pin points are made to occupy recesses to oneor the other side of the central recess.

In Fig. 11, the equivalent of the bearing pins 51 in Fig. 3, take the shape of the bearing screws 51. These are located outside of the plane of alinement of the diaphragm, fulcrum screws, bearing pins, and needles, but on being adjusted, accomplish the same results above alluded to.

In Fig. 13, the same result is obtained. So it will be seen that while the various constructions inhthe three forms of the reproducer are quite different, still there is one underlying principle that governs all and operates to produce a reproducer of a great range of adjustment and consequently applicable to a wide range of purposes.

While the-construction and arrangement of the reproducer as herein described and claimed, is that of a generally preferred form, obviously modifications and changes may be made without departing from the spirit of the invention or the scope of the claims.

I claim 1. In a reproducer, a frame, a needle bar, fulcrum means therefor carried by the frame, axially opposing adjustable flexible bar-supporting pins, and intermediate elements carried by the needle bar and engaged by said pins.

2. Supporting means for a fulcrumed needle bar, comprising adjustable resilient bar-carried yoke springs, each with a minute recess; and a flexible adjustable bearing pin with a point in unconnected but frictional contact with the recess of each spring.

3. A reproducer, including a frame with under-reaching brackets, an intermediately situated needle bar, fulcrum means on the frame engaging the bar on top, resilient means laterally adjustably mounted on the needle bar, and flexible bearing means axially opposing the fulcrum means, adjustable in the under-reaching brackets.

4. A reproducer, including a frame with under-reaching brackets, an intermediately situated needle bar with doubled yoke springs attached at one end thereto, bar fulcrum means carried by the frame and engaging the top of the needle bar, and flexible bar-supporting means in frictional contact with the unattached ends of said springs.

5. Supporting means for a fulcrumed needle bar, comprising a pair of resilient doubled yoke springs, adjustably connected to the bar with free ends extending in opposite directions; and bracket-carried adjust-able flexible bearing pins in pointed contact with the free spring ends.

6. A reproducer, comprising a frame with brackets, a compressibly mounted diaphragm with a stylus bar including a needle bar partially embraced and thus protected by said brackets, fulcrum members for the needle bar, and adjustable flexible bearing structure, including flexible and adjustable bearing pins in the brackets with companion needle bar-carried adjustable means having depressions for receiving portions of said bearing pins.

7. A reproducer, comprising a frame with underreaching bracket structure, and a diaphragm; a connected stylus bar including a needle bar located beneath the edge of the frame within said bracket structure, adjustable fulcrum screws on the frame for the needle bar, doubled oppositely opening yokes carried by the needle bar and including free resilient ends, and flexible adjustable hearing pins in pointed engagement with said free portions at the respective sides of the plane of the diaphragm.

S. In a reprodueer, a fulcrumed needle bar, a flexible adjustable bearing, and adjustable means carried by the needle bar with which said bearing engages.

WILLIAM T. LAKIN. 

